Transmission mechanism



1951 v I LE ROY H. FRAILING 2,577,413

TRANSMISSION MECHANISM 2 SHEETS-SHEET 2 Filed April 10, 1945 INVENTOR. ,4? M y H57 BY a} I42 I43 W Y 7 ATTOR NEY5 Patented Dec. 4, 1951 TRANSMISSION MECHANISM.

Le Roy H. Frailing, Detroit, Mich., casino! to Packard Motor Car Company, Detroit, Mich., a

corporation of Michigan Application April 10, 1945, Serial No. 587,523

Claims.

This invention relates to transmission mechanism that may be conditioned to drive either forwardly or reversely.

An object of the invention is to provide a compact transmission mechanism of the type referred to through the use of planetary gearing having forward and reverse control brake devices concentric with and telescoping the end portions thereof.

Another object of the invention is to provide transmission mechanism with fluid control means operable to condition change speed gearing for forward or reverse drive.

Another object of the invention is to provide a fluid control system for change speed gearing in which a valve selects forward or reverse drive through the gearing and other valves select the driving speed of the gearing.

A further object of the invention is to. provide a single engagement clutch between .a' driven member and forward and reverse gearing connected to a fluid clutch that canbe engagedto establish either the forward or the reverse drive.

Other objects of the invention will app ar from the following description taken in connection, with the drawings, which form a part of this specification.

Fig. 1 is a sectional view of a transmission mechanism incorporating the invention;

Fig. 2 is a sectional view of a brake device taken on line 2-2 of Fig. 1;

Fig. 3 is a sectional view of the torque-speed control and connecting device between two shafts taken on line 3--3 of Fig. 1;

Fig. 4 is a diagrammatic view of the devices controlling the transmission mechanism for neutral;

- Figs. 5 to 9 show the valve device diagrammatically in various positions of adjustment.

Referring to the drawings by characters of reference, the power transmission mechanism as shown comprises generally a rear portion of the housing of an internal combustion engine I8, fluid coupling I I, planetary gearing I2 and clutch means I3.

The engine crankshaft I4 is fixed to the fluid coupling impeller I5 which acts as the driver for two runners I6 and I1 associated with drive shafts I8 and I9 for driving the planetary gearing, such mechanism comprising the power input means. The planetary gearing is connected to power output means consisting of driven shaft 20, tail shaft 2| and propeller shaft 22 for operating a conventional vehicle drive axle (not shown), the tail shaft and propeller shaft being connectible by clutch means I3. Runner I6 is drivingly connected with shaft I 8 by a spring type overrunning clutch 24 while runner I1 is splined at 25 to shaft I9.

The planetary gearing includes drive gear 26 fixed to rotate with shaft I8, drive gear 21 fixed to rotate with shaft I9 and driven gear 28 splined to shaft 28 at 23. Planet gear 29 meshes with gear 26, planet gear 38 meshes with gear 21 and planet gear 3I meshes with gear 28. There is also a planet gear 32. These planet gears may be formed separately and fixed together or they may be formed integral as shown and are referred to as a planetary unit. There may be one or more of these units rotatably mounted on pins 33 fixed to the carrier. The ratios of the pairs of gears 21, 38 and 26, 29 are such that the drive through each pair is different. Fluid in the coupling I I is circulated by impeller I5 first through runner I8 and then runner I! in series, such coupling operating on the Fottinger principle. The shaft I8 will first be driven through clutch 24 to provide low speed drive through gears 26, 29, 3I and 28 and as the impeller speed and fluid pressure increases the second runner II will drive shaft I9 and through gears 21, 38, 3I and 28 will take over the drive at a higher speed. As the planet units are integral, shaft I8 will, when it takes over, drive the planet units at a speed that will cause shaft I8 to overrun runner I6. The planetary gearing will be ineffective to drive through the pairs of gears unless the carrier is held to prevent is retrograde rotation and brake means 35 is provided for this purpose. a

The fluid coupling II, gearing I2 and clutch means I3 are housed in a casing comprised of sections 38, 31 and 38. Casing section 36 encloses the fluid coupling and is fixed to the engine housing I0, casing section 37 encloses the change speed gearing I2 and easing section 38 encloses the clutch means. The rear wall 39 of casing section 36 serves to support the drive shafts I8 and I9 while the wall 40 of casing section 31 serves to support shaft 28 which pilots in sleeve 4| extendanchored to adjacent brake band sections as shown in Fig. 2. When the band 45 is engaged, retrograde rotation of the carrier 34 is prevented. When the band 45 is released, the brake drum 42 is free and the carrier 34 to which it is fixed is free to rotate in either direction.

Third speed or direct drive through the planetary gearing is obtained by locking two elements of the planetary gearing so that it will rotate as a unit. This drive is obtained by clutch means 50 looking the carrier 34 to shaft 20 through clutch housing secured to flange 52 on shaft 28 by bolts 53. Carrier 34 is splined to clutch member 54 and such member and housing 5| are slotted to receive tongues of alternate clutch plates 55 and a pressure ring 55 is actuated to engage the clutch plates to establish direct drive. The pressure ring is normally disengaged by coil springs I9.

The connection between flange 52 on shaft 25 and shaft 22 includes a torque-speed control device, see Fig. 3. F'lyweights 51 are carried by bushings 58 mounted on bolts 53. Arms 59 extend from shaft 2| and are slidably mounted in slots formed in cylindrical members 50 rotatably mounted in sleeves 5| flxed to the flyweights. In first and second speed, the drive passes from shaft 25 and its flange 52 and bolts 53 to the iiyweights 51 and through members 59 and sleeves 5| to arms 59 of shaft 2|, the carrier 34 being held stationary. When the clutch is engaged for high speed, the brake means 35 is disengaged and the entire planetary gearing is locked together with the drive flowing from shaft as in second speed and also through the carrier and clutch to the flange 52.

Planetary gear 32 meshes with gear 53 rotatably mounted on shaft I9. When this gear 53 is released it will be driven idly by the planetary unit but when braked it will cause the planetary units to turn rearwardly and thereby drive shaft 28 in reverse. Brake means for gear 53 is indicated generally by numeral 54, see Figs. 1 and 2. The gear 53 is provided with a drum 55' on which the forward end of carrier 34 has a bearing and has a rim adapted to be engaged or released by brake means similar to that employed for braking the carrier. A sectional band 55 is mounted in casing 51 fixed to casing 31 and is normally expanded to release drum 55 by spring members 48 acting upon adiacent ends of the band sections. A rubber tube 58 is arranged between casing 51 and the brake band and when the tube is inflated it will contract the brake band to engage and hold the drum 55 and gear 53 stationary.

The brake means for holding the carrier 34 and the reverse gear 53 are similar, concentric and arranged at opposite ends of the planetary gearing with their drum rims extending toward the central portion of the gearing and in telescoping relation with the end portions of the gearing. The construction provides a compact structure with relatively large brake surfaces so that the diameter and overall length of the transmission mechanism can be relatively small. This arrangement of the reverse drive mechanism will occupy unused space so that overall length of the transmission is not increased for this purpose.

The clutch means I3 is operative to entirely disconnect or to establish the drive between shafts 2| and 22 when the planetary gearing is conditioned for either forward or reverse drive. One of the clutch members is formed as a disk 18 on the forward end of the propeller shaft 22 and the shiftable clutch member II is slidably splined on shaft 2| and has teeth 12 adapted to engage with teeth 13 on the disk. The member II has a flange portion that may be engaged by suitable manually operable shift mechanism (not shown), and also for use as a part of synchronizing mechanism. Synchronizer disk 14 has an internal cone friction surface 15 for engaging a similar peripheral surface on disk 10 to bring shafts 2| and 22 to the same speed before engaging the teeth 12 with teeth 13. The disk 14 is located between the flange of clutch member II and the disk 10 while another synchronizer disk 15 is located in advance of the flange of the clutch member I I. These synchronizer disks have a multi-diameter pin 11 flxed thereto that passes through opening 18 in the clutch member flange. Such opening is of larger diameter than the pin therein and has a beveled end portion facing a similar beveled surface 88 on the pin. An angular spring 8| passes through the flange opening and engages the synchronizer disks. As the clutch flange is shifted to engage teeth I2 with teeth 13, it bears against spring 8| and will shift the synchronizer structure to press disk 14 into frictional engagement with disk 10. The synchronized structure will beheld by the propeller shaft and rotated thereby. should the vehicle be moving at that time, while beveled surface 88 of pin 11 will overlie a portion of the beveled end of the flange opening to block further movement of the clutch member to engage the clutch teeth. When the speed of the shaft 2| is brought to the same speed as shaft 22 and then slightly beyond, the reversal of direction of drive will cause the beveled surface 88 of pin 11 to move out of its overlying position with respect to the beveled end of the flange, thereby freeing the clutch member and permitting it to continue on to engage teeth 12 with teeth 13 to provide a positive drive connection. Should engagement of teeth I2 with teeth "be desired when shaft 22 is stationary so that there is no relative reversal of direction of rotation between shafts 2| and 22, the pin 11 can be forced out of blocking position by increased pressure on the clutch flange which in turn forces beveled surface of pin 11 to move along the beveled end of the flange opening until the pin is free of the flange.

The brakes 54 and 35 and the clutch 50 are controlled by a hydraulic system in which fluid flow may be selected for forward or reverse drive by manually operated means. The three driving speeds through the planetary gearing may be automatically established, as dictated'by vehicle operating conditions, in either forward or reverse drive.

The hydraulic system includes two star type pumps 8| and 82, see Figs. 4 to 9. Pump 8| has one rotor 83 splined to a housing section 84 of the impeller l5 and another rotor section 85 mounted to rotate freely in a chamber between casing wall 39 and a cover plate 85. Pump 82 has one rotor 81 splined totail shaft 2| and another rotor section 81' mounted to rotate freely in a chamber between wall 88 and cover plate 89. Pump 8| has a fluid intake conduit 99 and pump 82 has an intake conduit 9|, such conduits being connected with a suitable source of mild such as the sump for lubricating oil in the transmission mechanism. Pump 8| has an outlet conduit 92 and pump 82 has an outlet passage 93, such passages leading to the housing 4 of the flow. control device 94. Conduit 93 also connects with passage 95 extending axially through shaft 2I and communicating at one end with passage 96 that is open to chamber 91 in flange 52 in which is mounted piston 98 for actuating the clutch pressure plate 56, see Fig. 1. Passage 95 is connected with a passage 99 extending radially to the exterior of shaft 2| beneath one of the flyweights 51 and a stem I00, fixed to such flyweight, is movable in the radial passage. The stem is engageable with a ball valve IOI normally urged to engage a seat member I02 by coil spring I03, see Fig. 3. When the valve is seated fluid from pump 82 flows to chamber, 91 and acts against piston 98 to engage clutch 50 but when the valve is open the fluid will flow through radial passage 99 and passage 96 will be relieved so that springs 19 will disengage clutch 50. As one of the flyweights actuates stem I00, the valve IOI will be controlled in accordance with the flyweight position which is controlled by torque and speed. Engine torque acting through shaft 20 and pins 53 tends to hold the flyweights inwardly while the speed of shaft 2I acting through arms 59 acts to move the flyweights outwardly and these oppositely acting forces will determine the pivotal position of the flyweights to thus control the position of valve I I.

Conduit I04 connects the interior of brake tube 68 with the control device housing H4 and conduit I connects the interior of tube 41 with the control device housing, such conduits being selectively connectible with pump 8| by the shifting of a cylindrical valve I06 arranged in a bore I 01 in the control device housing I I4. The pump outlet conduits 92 and 93 and the brake inlet conduits I04 and I05 are all arranged in spaced relation and in communication with bore I01. Valve I06 is preferably shifted by mechanism operable by the vehicle driver. Such mechanism comprises a link rod I08 pivoted to the valve and a lever I09, a control rod IIO extending adjacent steering column III, a link II2 connecting lever I09 with the rod and an arm I'3 on the rod to be manipulated by the vehicle driver. Valve I06 will be shifted axially of link rod I08 when rod I I0 is rotated through means of link I I2 and lever I09. The control device housing has a vent port II 5 leading from the bore between conduits I04 and I05 and another vent port II6 leading from the bore adjacent conduit 93.

Valve I06 has a plurality of reduced diameter portiom H1, H8, H9 and I20 along its length that are spaced to provide a fluid flow selection for establishing either forward or reverse drive through the planetary gearing.

The control device housing also has bores I2I and I22 in which are mounted valves I23, I24. and I40. These valves are narallel with the forward and reverse valve. Passage I25 connects bores I01 and I2I, passage I26 connects bores I2I and I22 and passage I 21 connects bores I01, I2I and I22. Passage I28 extends from bore I01 through one end of the housing and communicates with conduit I29. Passage I30 in the housing connects passages I28 and I25 between bores I01 and I2I and a spring seated valve I3Ipis arranged in passage I28 between passage I30 and conduit I29. Vent conduits I 32 and I33 connect the bore I 22 with conduit I34 which communicates with conduit I35 leading to passage I36 communicating with the interior of the fluid coupling II. Pressure relief valve I31 is arranged in conduit I35. Valve I24 has a reduced diameter portion I38 and valve I23 has a reduced diameter portion I39. Pa'ssage I52 in the housing connects bore I2I with passage I29 between valve I3I and passage I29.

Sleeve valve I40 is mounted in bore I22 and the head extension I4I of valve I24 is slidably mounted therein. An actuator I42 abuts the end of valve I40 and is pivotally connected to lever I43 connected to a Bowden wire actuator I44 extending to the vehicle instrument board I 45. Valve I24 is connected with the engine accelerator pedal I46 bylinkage I41, bell crank I48 and link I49. I

Conduit I50 connects conduits 92 and I35. A spring seated valve I51 is arranged in conduit I50. This valve I5I will remain seated until a high fluid pressure is developed in conduit 92, such pressure being for example 450 lbs. Valve I31 is arranged to be unseated at a low pressure. for example 5 lbs. and valve I23 is arranged to be shifted against the action of its spring when pressure in passage I21 reaches lbs. Valve I3I will be seated until the pressure in conduit I28 reaches a medium pressure, for example lbs.

The drive from the transmission can be established or broken by shifting clutch I3. When the clutch is shifted to engage teeth 12 with teeth 13 the driving connection between shafts 2I and 22 will be established and when such teeth are disconnected the drive between such shafts will be broken. Forward or reverse drive may be selectively established by the position of valve I 06 and such valve is shifted axially by the vehicle driver turning arm II3 to rotate shaft IIO. Three driving speeds can be established automatically through the transmission mechanism. Provision is made to overrule the high speed drive and establish a lower speed drive through operation of the accelerator I46. Provision is made to provide a positive drive in first or second speed, such positive drive and the shift from high to second speed drive being obtainable even though the automatic controlling means dictates that the high speed clutch 50 should be engaged.

Neutral is obtainable in the transmission mechanism when the clutch I3 is disengaged. If the vehicle is standing still and the engine is operating pump 82 will be inactive but pump 8I will be driven by the housing section 84 of the impeller I5. The control mechanism and its adjustment for neutral is shown in Fig. 4. As pump 82 is not operating there will be no fluid pressure exerted against clutch 50. The selector valve I06 will be in forward driving position so that conduit I04 leading to the brake for establishing reverse drive will be open to vent II5 so that there will be no fluid pressure acting to hold the reverse brake drum to establish reverse drive. Fluid from pump 8I will pass through conduit 92 and past the reduced portion II1 of the selector valve into passage I28 from which it will flow through passages I30, I25, bore I2I and passage I26 to bore I22 and around the reduced portion I38 of valve I24 to the vent conduits I32 and I34. Thus fluid is vented through conduit I05 to tube 41 and the brake band 45 will be disengaged from brake drum 42 thereby leaving the carrier 34 free to rotate in a reverse direction so that no drive will be imparted from the planetary gearing to shaft 20. As soon as the accelerator pedal is pressed downit will shift valve I24 in a direction closing passage I26 50 that fluid will flow to tube 41 and engage the associated band 45 with drum 42 thereby conditioning the planetary gearing for first or second speed drive provided clutch I3 is engaged. Thus when in neutral there will be no fluid flow to either one of the brake bands or to the clutch, so even though the clutch I is engaged there will be no drive from the planetary gearing to shaft 2I. Of course disengagement of clutch I3 will prevent any driving connection from the planetary gearing to shaft 22 and with the clutch I5 engaged and the accelerator pedal released the planetary gearing will not be conditioned to drive. with this arrangement the driver of a vehicle may come to a standstill at a stop light and if he does not disengage clutch II the vehicle will remain stationary but will start up in first immediately upon depression of the accelerator pedal as this will discontinue ventin of conduit I05.

Fig. 5 shows the control device in its position of adjustment whereby first or second speed drive from the planetary gearing to shaft 22 is obtained. It must be assumed that clutch I0 is engaged and that the speed of the vehicle is below that which will cause the flyweights 51 to move out far enough to permit valve IM to seat. The adjustment of the control mechanism for first and second drive is substantially the same as that for neutral except that clutch I3 must be engaged and the ac celerator pedal must be depressed. Depression of the accelerator pedal shuts off venting through passage I25 so that the fluid will flow from pump 0| through conduit 92 around portion I I1 of valve I00 and through passages I20, I00 and I20 to conduit I05, the flow from passage I25 to conduit I05 being through bore I01 around the reduced portion II! of the selector valve. Fluid flowing into tube 41 will contact brake band 45 so that it engages brake drum 42 to hold the planetary carrier 34 stationary. As the carrier cannot turn in a retrograde direction, drive will be from the first runner I0, clutch 24, shaft I0 to gear 20, and from such gear to gears 29,:0I and 20 driving shaft 20 in a forward direction, Shaft 20 is connected with shaft 2| through the torque-speed mechanism and drives such shaft and shaft 22 in a forward direction. The drive may come from runner I1, shaft l0, gears 21, 00, 0| and 20 to shaft 20. The runners I0 and I1 are in series so that the fluid flow therethrough will act initially through runner I0 to drivev the planetary gearing in the low speed gear ratio but as the fluid pressure increases in the fluid clutch, runner I 1 will take over the drive so that second speed drive is provided and when this occurs the unit planet gear will be rotated at a speed driving shaft I0 faster than runner I0 so that it overruns the same through means of the one-way clutch 24. As the vehicle speed is low flyweights 51 will hold valve IOI open so that the fluid from pump 02 will bypass the clutch 50 through passage 00. The shift of the drive between first and second speed takes place automatically in accordance with operating conditions present in the fluid coupling.

The control device positioned to condition the planetary gearing for third or high speed drive is shown in Fig. 6. At some predetermined speed and toroue condition the flyweights 51 will move outwardly a sufllcient distance to permit valve IN to seat whereupon fluid from pump 02 and conduit 90 instead of venting through passage 00 as it would in first and second speed drives will be blocked off so that it will have to pass through passage 95 into chamber 01 and will thereby move piston 00 to engage the clutch plates 55 against the releasing action of springs 10. In the meantime it is necessary to vent the fluid from the first and second speed brake device and this occurs when the pressure reaches 80 lbs. in

passage I21 and bore "I, the connection of passage I21 with conduit being around the valve portion I20. This pressure is necessary to engage clutch 50 and it will also act to move valve I20 to the left so that its reduced portion I00 will connect passage I25 with passage I52 and thereby vent any fluid that would otherwise flow to the brake tube 41. Engagement of clutch 50 will lock up the planetary gearing so that the drive will pass to shaft 20 and flange 52 through the clutch housing and also through gears 21, 00, SI and 20. The planetary gearing will thus rotate forwardly at the same speed as the second runner I1, which except for a small amount of slip, will rotate at substantially the same speed as the impeller I5 driven by crankshaft I4. In the adjustments. of the control device for first, second and high speed, the reverse drive conduit I04 will be open to the vent passage II 5 around the reduced portion IIO of valve I00 and the vent passage IIO vwill be closed by valve I00. Likewise under the same conditions passage I21 will be closed by valve I40 so that fluid cannot drain into conduit Ill. It is to be noted also that in first, second and high speed adjustments of the control device fluid from pump 0I will flow to conduit I35 through conduit I34 and will be relieved by valve I01 to maintain a pressure of 5 lbs. of fluid flowing to the fluid coupling and this flow will be sufficient to maintain a predetermined volume of fluid in the coupling II.

When the torque-speed device is in position engaging clutch 50 to condition the planetary gearing for high speed drive its effect may be overcome by pressing the accelerator I41 down beyond wide open throttle position whereupon valve I24 is shifted to carry valve I40 therewith so that its reduced portion will provide a connection through the bore I 22 containing valve I24 to relief conduit I00 as shown in Fig. 7. Under such circumstances, valve I40 will be moved to the left so that fluid from pump 82 will drain out through conduits 90 and passage I21, bore I22 and conduits I00 and I34 to thereby relieve pressure against piston 98 so that spring 10 can release the clutch 50. As the pressure is relieved in passage I21 valve I23 will move to the right and shut oil venting of passage I25 through passage I52 and fluid from pump 8| will flow through conduit I05 to the tube 41 which will expand and cause contraction of brake band 45 so that it engages brake drum 42 and conditions the gearing for first and second speed drive. As long as the accelerator pedal is held beyond wide open throttle position this lower speed drive will be established by the location of valve I40, but as soon as the accelerator pedal is allowed to return to approximately one-third open throttle position then valves I24 and I40 will return to the positions they occupied during high speed drive so that venting of passage I21 ceases and the clutch is again engaged and conduit I 05 to the first and second speed brake device is again vented through passage I52. This adjustment of the mechanism is sometimes called kickdown. It will be noted that the control mechanism will dictate high speed drive through the planetary gearing but it may be overruled by the operation of the accelerator pedal and the associated valves.

The control mechanism may also be adjusted to provide a positive first or second speed drive as shown in Fig. 8, even though the torque-speed mechanism dictates high speed drive. This adjustment provides a positive lower speed drive and is useful when it is desired to use the engine as a brake such as when-going downhill. This adjustment is obtained by adjustment of valve I40 through means of lever I43 and the Bowden wire I44. By pulling the knob on the Bowden 'wire toward the driver, lever I43 will move the actuator I42 inwardly of the bore for valve I24 and will carry the valve I40 therewith so that its reduced portion provides a connection between passage I21 and conduits I33 and I34. Thus fluid for operating the clutch 50 will be vented as it was in kickdown" and it will be impossible for the automatic mechanism to establish high speed drive even though the speedtorque conditions may so dictate. When in this adjustment the drive will be in either first or second speed depending upon operating conditions in the fluid clutch as pointed out in the description directed to such driving speeds.

Provision is also made for obtaining a reverse drive at either first or second speed previously described and the adjustment of the control device for obtaining reverse drive is shown in Fig. 9. In order to obtain reverse drive valve I06 is shifted toward the left, looking at the diagrammatic figures, by turning the arm H3 to a position where the reduced portion II8 of the valve provides a connection between conduits 92 and I04. In this valve position conduit-- I is connected to the vent opening I I5 around the reduced portion I I9 of the selector valve and conduit 93 from pump 82 is connected with the vent passage H6 around the reduced portion I20 of the selector valve. Fluid flowing through conduit I04 will expand the tube 68 and contact brake band 66 to engage brake drum 65 which will hold gear 63 stationary. The carrier 34 is free to rotate and rotation of the planet units around stationary gear 63 will cause a reverse rotation of gear 28, which rotation will be imparted to shaft 20 and through the torque-speed mechanism to shaft 2| so that when clutch I3 is engaged the propeller shaft 22 will be driven in a reverse direction at either first or second speed depending upon whether runner I6 or I! is doing the driving. Obviously high speed will not be obtainable because the fluid flow to the clutch 50 is vented.

It will be understood that various forms of the invention other than that described above may be used without departing from the spirit or scope of the invention. V

What is claimed is:

1. Transmission mechanism comprising drive and driven shafts, planetary gearing connecting said shafts and adapted to produce a low forward speed, a fluid operated brake device for establishing said low speed, a reverse gear meshing with an element of said gearing, a device for braking said reverse gear, a clutch device for locking the planetary gearing, a pressure fluid system connected with said brake and clutch devices, a valve controlling flow to the clutch device responsive to the speed of the driven shaft, a valve automatically actuated by pressure fluid used to engage the high speed clutch for venting the low speed brake, and a manually operable master valve controlling fluid flow selectively to said reverse brake device and said clutch valve device.

2. In a transmission mechanism for motor vehicles the combination with drive mechanism having a fluid coupling means driven by the vehicle motor and connectible with planetary gearing including a multiple gear planet unit and a carrier, means driven by the planetary gearing,

10 a low speed brake normally engaged to prevent retrograde movement of the carrier to establish forward drive, clutch means for locking the planetary gearing, a gear meshing with the planet unit to establish reverse drive when braked, and a normally disengagedbrake for said gear, of control means for the brakes and clutch comprising a fluid system having two fluid supply pumps, one driven by the vehicle motor and the other by the planetary gearing driven means, fluid connections between the motor driven pump and the brakes, a fluid connection between the other pump and the clutch, a valve means in the system operable to selectively control fluid flow to the brakes, and a torque-speed controlled valve device controlling fluid flow to the clutch.

3. Transmission mechanism comprising drive and driven shafts, planetary change speed gearing connecting said shafts and including brake means for establishing low and reverse drives and clutch means for establishing a high speed drive through the gearing, a pressure fluid system connected to control the brake and clutch means, a manually operable valve in the fluid system having one position rendering the reverse brake means effective and the low speed brake means and the clutch means ineffective and another position conditioning the low speed brake means and high speed clutch means for operation and the reverse brake means for disengagement, a torque-speed actuated valvein the system controlling fluid flow to the clutch, and a valve automaticaliy actuated by pressure fluid used to engage the high speed clutch for venting the low speed brake means when the clutch is engaged.

4. Transmission mechanism comprising drive and driven shafts and adapted to produce a low forward speed, a fluid operated brake device for establishing said low speed, planetary gearing connecting said shafts, a reverse gear meshing with an element of said gearing, a device for braking said reverse gear, a clutch device for locking the planetary gearing to provide a direct drive through the gearing, a pressure fluid system connected with said brake and clutch devices, a valve controlling flow to the clutch device, means responsive to the speed of, and torque transmitted through, the driven shaft for controlling the valve, a valve automatically actuated by pressure fluid used to engage the high speed clutch for venting the low speed brake, and a manually operable master valve controlling fluid flow selectively to said brake device and said clutch valve device.

5. In a transmission mechanism for motor vehicles having a fluid coupling power input means driven by the vehicle motor and connected with planetary gearing conditioned through means including brakes for establishing forward or reverse drive to output means, control means for the brakes comprising a fluid systemhaving a fluid pump driven by the input means, valve means operable to connect the pump with the forward brake and to shut off fluid flow to the reverse brake in one position of adjustment, and to open the system between the pump and the reverse brake and shut off fluid flow to the forward brake in another position of adjustment, additional valve means for opening the system between the pump and the forward brake, centrifugally operated means driven by the output means and connected to the additional valve means to operate the said additional valve means in accordance with the speed of the vehicle and means responsive to the torque transmitted through the output fnetns for opposln: the centrlfuully operated Number means. 2,021,550 LE ROY FRAILING. 2,055,325 2,091,391 REFERENCES CITED 2,339,734 The following references are of record 21 the I 3333-593 file of this patent: UNITED STATES PATENTS 2,352,212 Number Name Date 2,355,137

725,223 Crawford Apr- 2,38: 2,402,248 Hale June 19, 1946 7 787,908 Ford Apr. 2 o. 924,956 Ball June 15, 1909 I 70mm PATENTS 1,026,448 Marston May 14, 1912 um r Country Date 1,883,500 Bjorndal Oct.18,1932 1,883 name 20, 192-: 

